664434654517620 has 96 divisors (see below), whose sum is σ = 2362434327187200. Its totient is φ = 151870778174592.

The previous prime is 664434654517603. The next prime is 664434654517639. The reversal of 664434654517620 is 26715456434466.

664434654517620 is a `hidden beast` number, since 6 + 6 + 4 + 4 + 3 + 4 + 6 + 54 + 517 + 62 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 87888178035 + ... + 87888185594.

It is an arithmetic number, because the mean of its divisors is an integer number (24608690908200).

Almost surely, 2^{664434654517620} is an apocalyptic number.

664434654517620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

664434654517620 is an abundant number, since it is smaller than the sum of its proper divisors (1697999672669580).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664434654517620 is a wasteful number, since it uses less digits than its factorization.

664434654517620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175776363654 (or 175776363646 counting only the distinct ones).

The product of its (nonzero) digits is 348364800, while the sum is 63.

The spelling of 664434654517620 in words is "six hundred sixty-four trillion, four hundred thirty-four billion, six hundred fifty-four million, five hundred seventeen thousand, six hundred twenty".